Although the Federal Aviation Administration has lifted some restrictions on flight training schools, Florida’s billion-dollar industry remains mostly grounded after almost two weeks without revenue.

The FAA immediately grounded all aircraft after Sept. 11’s terrorist hijackings and subsequent crashes. In the following days, restrictions were rescinded — first commerical airplanes, then some operating under instrument flight rules, as long as they only traveled from airport to airport, and finally some operations using visual flight rules.

But a restriction on visual flight rules operations, which includes most flight training businesses, remains in effect for the areas surrounding the nation’s busiest airports, which includes Miami International Airport. Kendall-Tamiami, North Perry, Opa-locka and Opa-locka West airports are in the restricted space.

Flight-training schools have been hit so hard that the president of the Aircraft Owners and Pilots Association testified before the Congressional Committee on Transportation and Infrastructure Tuesday, recommending a relief plan to assist flight schools nationwide.

"The short-term effect of grounding VFR flights has resulted in countless general aviation related businesses pushed to the brink of extinction," association president Phil Boyer wrote in his submitted statement.

"Small flight schools, already hard hit by dramatic increases in aviation insurance, will go out of business without some sort of federal relief."

Indeed, losses of several thousand dollars a day have made it difficult for many local companies to return to the skies.

"Our status is, we’re basically closed," said Thomas Shaffer, owner of Silver Express flight school at Kendall-Tamiami Airport. He said his company had 21 employees before the attacks on New York City and Washington, DC. Now, he said, "Planes are sitting on the ground, rotting. Bills are piling up. There’s no money coming into the register. It’s about as bad as it can be."

Mr. Shaffer said that after a Sept. 21 ruling by the FAA lifting part of the restriction, a few customers who were allowed to fly under the limits started to trickle back. Still, he said, he has not been able to bring back any of his employees full time. Flight instructors, who are paid according to the number of hours they bill, are losing 60% to 70% of their normal income, Mr. Shaffer said. He estimated a loss of about $3,500 a day while his school was shut down.

"We’re barely operating – we’re not at a sustainable level," he said. "These effects are going to take a while to shake out. We’re still day-to-day."

Mr. Shaffer’s troubles are shared by flight training schools nationally. There are about 3,200 schools in the US and 215 in Florida.

Warren Morningstar, vice president of communications for the Aircraft Owners & Pilots Association in Maryland, said the flight school industry likely lost between $10 million-$15 million daily during the FAA shutdown.

"We know of some that have been forced to close their doors and a lot of cases had employees furloughed," Mr. Morningstar said. "I think at this point, we don’t know how this is all going to shake out."

State Aviation Manager Bill Ashbaker said flight training brought more than $1 billion a year into Florida, whose schools train about 20% of the world’s pilots.

"Especially smaller schools have a lot of investments," Mr. Ashbaker said. "It’s really hurt them a lot. Undoubtedly, there have been some that have had to file for bankruptcy protection."

Air Repair Inc., a flight school based at Opa-locka, is one company questioning its future. During the week and a half after the terrorist attacks, the company – which also rents out aircraft and provides maintenance and fuel to other aircraft – only had two or three flights.

"We’re dying," said Terry Ritter, owner of Air Repair. He said he cut half of his staff following the shutdown. "We’re losing dollars by the day – copious amounts. There are schools like mine that can’t afford to stay sitting on the ground. We’re going to go broke quickly."

If flight schools fold, associated businesses will be in trouble, too, say industry experts. Some maintenance companies have already reported major slowdowns in business. And even further down the road, the combination of major airlines’ layoffs and the many flight schools’ closings could form the foundation for a pilot shortage.

"The majority of airline pilots come out of the civilian sector. The aviation service to the economy is much more than just airlines," Mr. Morningstar said. "There is the potential for a very serious, long-term impact."